/* * Copyright (c) 2001 Atsushi Onoe * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * Alternatively, this software may be distributed under the terms of the * GNU General Public License ("GPL") version 2 as published by the Free * Software Foundation. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * $FreeBSD: src/sys/net80211/ieee80211_node.c,v 1.22 2004/04/05 04:15:55 sam Exp $ * $DragonFly: src/sys/netproto/802_11/Attic/ieee80211_node.c,v 1.1 2004/07/26 16:30:17 joerg Exp $ */ #include "opt_inet.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #endif static struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *); static void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *); static void ieee80211_node_copy(struct ieee80211com *, struct ieee80211_node *, const struct ieee80211_node *); static uint8_t ieee80211_node_getrssi(struct ieee80211com *, struct ieee80211_node *); static void ieee80211_setup_node(struct ieee80211com *ic, struct ieee80211_node *ni, uint8_t *macaddr); static void _ieee80211_free_node(struct ieee80211com *, struct ieee80211_node *); MALLOC_DEFINE(M_80211_NODE, "80211node", "802.11 node state"); void ieee80211_node_attach(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; lwkt_token_init(&ic->ic_nodetoken); TAILQ_INIT(&ic->ic_node); ic->ic_node_alloc = ieee80211_node_alloc; ic->ic_node_free = ieee80211_node_free; ic->ic_node_copy = ieee80211_node_copy; ic->ic_node_getrssi = ieee80211_node_getrssi; ic->ic_scangen = 1; } void ieee80211_node_lateattach(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; struct ieee80211_node *ni; ni = (*ic->ic_node_alloc)(ic); KASSERT(ni != NULL, ("unable to setup inital BSS node")); ni->ni_chan = IEEE80211_CHAN_ANYC; ic->ic_bss = ni; ic->ic_txpower = IEEE80211_TXPOWER_MAX; } void ieee80211_node_detach(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; if (ic->ic_bss != NULL) (*ic->ic_node_free)(ic, ic->ic_bss); ieee80211_free_allnodes(ic); lwkt_token_uninit(&ic->ic_nodetoken); } /* * AP scanning support. */ /* * Initialize the active channel set based on the set * of available channels and the current PHY mode. */ static void ieee80211_reset_scan(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; memcpy(ic->ic_chan_scan, ic->ic_chan_active, sizeof(ic->ic_chan_active)); /* NB: hack, setup so next_scan starts with the first channel */ if (ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC) ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX]; } /* * Begin an active scan. */ void ieee80211_begin_scan(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; /* * In all but hostap mode scanning starts off in * an active mode before switching to passive. */ if (ic->ic_opmode != IEEE80211_M_HOSTAP) { ic->ic_flags |= IEEE80211_F_ASCAN; ic->ic_stats.is_scan_active++; } else ic->ic_stats.is_scan_passive++; if (ifp->if_flags & IFF_DEBUG) if_printf(ifp, "begin %s scan\n", (ic->ic_flags & IEEE80211_F_ASCAN) ? "active" : "passive"); /* * Clear scan state and flush any previously seen * AP's. Note that the latter assumes we don't act * as both an AP and a station, otherwise we'll * potentially flush state of stations associated * with us. */ ieee80211_reset_scan(ifp); ieee80211_free_allnodes(ic); /* Scan the next channel. */ ieee80211_next_scan(ifp); } /* * Switch to the next channel marked for scanning. */ void ieee80211_next_scan(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; struct ieee80211_channel *chan; chan = ic->ic_bss->ni_chan; for (;;) { if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX]) chan = &ic->ic_channels[0]; if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) { /* * Honor channels marked passive-only * during an active scan. */ if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 || (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) break; } if (chan == ic->ic_bss->ni_chan) { ieee80211_end_scan(ifp); return; } } clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan)); IEEE80211_DPRINTF(("ieee80211_next_scan: chan %d->%d\n", ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan), ieee80211_chan2ieee(ic, chan))); ic->ic_bss->ni_chan = chan; ieee80211_new_state(ic, IEEE80211_S_SCAN, -1); } void ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan) { struct ieee80211_node *ni; struct ifnet *ifp = &ic->ic_if; ni = ic->ic_bss; if (ifp->if_flags & IFF_DEBUG) if_printf(ifp, "creating ibss\n"); ic->ic_flags |= IEEE80211_F_SIBSS; ni->ni_chan = chan; ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)]; IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr); IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr); if (ic->ic_opmode == IEEE80211_M_IBSS) ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */ ni->ni_esslen = ic->ic_des_esslen; memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen); ni->ni_rssi = 0; ni->ni_rstamp = 0; memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); ni->ni_intval = ic->ic_lintval; ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; if (ic->ic_flags & IEEE80211_F_WEPON) ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; if (ic->ic_phytype == IEEE80211_T_FH) { ni->ni_fhdwell = 200; /* XXX */ ni->ni_fhindex = 1; } ieee80211_new_state(ic, IEEE80211_S_RUN, -1); } static int ieee80211_match_bss(struct ifnet *ifp, struct ieee80211_node *ni) { struct ieee80211com *ic = (void *)ifp; uint8_t rate; int fail; fail = 0; if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) fail |= 0x01; if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && ni->ni_chan != ic->ic_des_chan) fail |= 0x01; if (ic->ic_opmode == IEEE80211_M_IBSS) { if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) fail |= 0x02; } else { if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) fail |= 0x02; } if (ic->ic_flags & IEEE80211_F_WEPON) { if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) fail |= 0x04; } else { /* XXX does this mean privacy is supported or required? */ if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) fail |= 0x04; } rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); if (rate & IEEE80211_RATE_BASIC) fail |= 0x08; if (ic->ic_des_esslen != 0 && (ni->ni_esslen != ic->ic_des_esslen || memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0)) fail |= 0x10; if ((ic->ic_flags & IEEE80211_F_DESBSSID) && !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) fail |= 0x20; #ifdef IEEE80211_DEBUG if (ifp->if_flags & IFF_DEBUG) { printf(" %c %6D", fail ? '-' : '+', ni->ni_macaddr, ":"); printf(" %6D%c", ni->ni_bssid, ":", fail & 0x20 ? '!' : ' '); printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), fail & 0x01 ? '!' : ' '); printf(" %+4d", ni->ni_rssi); printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, fail & 0x08 ? '!' : ' '); printf(" %4s%c", (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "????", fail & 0x02 ? '!' : ' '); printf(" %3s%c ", (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? "wep" : "no", fail & 0x04 ? '!' : ' '); ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); printf("%s\n", fail & 0x10 ? "!" : ""); } #endif return fail; } /* * Complete a scan of potential channels. */ void ieee80211_end_scan(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; struct ieee80211_node *ni, *nextbs, *selbs; int i, fail; ic->ic_flags &= ~IEEE80211_F_ASCAN; ni = TAILQ_FIRST(&ic->ic_node); if (ic->ic_opmode == IEEE80211_M_HOSTAP) { /* XXX off stack? */ u_char occupied[roundup(IEEE80211_CHAN_MAX, NBBY)]; /* * The passive scan to look for existing AP's completed, * select a channel to camp on. Identify the channels * that already have one or more AP's and try to locate * an unnoccupied one. If that fails, pick a random * channel from the active set. */ for (; ni != NULL; ni = nextbs) { ieee80211_ref_node(ni); nextbs = TAILQ_NEXT(ni, ni_list); setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); ieee80211_free_node(ic, ni); } for (i = 0; i < IEEE80211_CHAN_MAX; i++) if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) break; if (i == IEEE80211_CHAN_MAX) { fail = arc4random() & 3; /* random 0-3 */ for (i = 0; i < IEEE80211_CHAN_MAX; i++) if (isset(ic->ic_chan_active, i) && fail-- == 0) break; } ieee80211_create_ibss(ic, &ic->ic_channels[i]); return; } if (ni == NULL) { IEEE80211_DPRINTF(("%s: no scan candidate\n", __func__)); notfound: if (ic->ic_opmode == IEEE80211_M_IBSS && (ic->ic_flags & IEEE80211_F_IBSSON) && ic->ic_des_esslen != 0) { ieee80211_create_ibss(ic, ic->ic_ibss_chan); return; } /* * Reset the list of channels to scan and start again. */ ieee80211_reset_scan(ifp); ieee80211_next_scan(ifp); return; } selbs = NULL; if (ifp->if_flags & IFF_DEBUG) if_printf(ifp, "\tmacaddr bssid chan rssi rate flag wep essid\n"); for (; ni != NULL; ni = nextbs) { ieee80211_ref_node(ni); nextbs = TAILQ_NEXT(ni, ni_list); if (ni->ni_fails) { /* * The configuration of the access points may change * during my scan. So delete the entry for the AP * and retry to associate if there is another beacon. */ if (ni->ni_fails++ > 2) ieee80211_free_node(ic, ni); continue; } if (ieee80211_match_bss(ifp, ni) == 0) { if (selbs == NULL) selbs = ni; else if (ni->ni_rssi > selbs->ni_rssi) { ieee80211_unref_node(&selbs); selbs = ni; } else ieee80211_unref_node(&ni); } else { ieee80211_unref_node(&ni); } } if (selbs == NULL) goto notfound; (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); if (ic->ic_opmode == IEEE80211_M_IBSS) { ieee80211_fix_rate(ic, ic->ic_bss, IEEE80211_F_DOFRATE | IEEE80211_F_DONEGO | IEEE80211_F_DODEL); if (ic->ic_bss->ni_rates.rs_nrates == 0) { selbs->ni_fails++; ieee80211_unref_node(&selbs); goto notfound; } ieee80211_unref_node(&selbs); /* * Discard scan set; the nodes have a refcnt of zero * and have not asked the driver to setup private * node state. Let them be repopulated on demand either * through transmission (ieee80211_find_txnode) or receipt * of a probe response (to be added). */ ieee80211_free_allnodes(ic); ieee80211_new_state(ic, IEEE80211_S_RUN, -1); } else { ieee80211_unref_node(&selbs); ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); } } static struct ieee80211_node * ieee80211_node_alloc(struct ieee80211com *ic) { struct ieee80211_node *ni; MALLOC(ni, struct ieee80211_node *, sizeof(struct ieee80211_node), M_80211_NODE, M_NOWAIT | M_ZERO); return ni; } static void ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) { FREE(ni, M_80211_NODE); } static void ieee80211_node_copy(struct ieee80211com *ic, struct ieee80211_node *dst, const struct ieee80211_node *src) { *dst = *src; } static uint8_t ieee80211_node_getrssi(struct ieee80211com *ic, struct ieee80211_node *ni) { return ni->ni_rssi; } static void ieee80211_setup_node(struct ieee80211com *ic, struct ieee80211_node *ni, uint8_t *macaddr) { lwkt_tokref ilock; int hash; IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr); hash = IEEE80211_NODE_HASH(macaddr); ni->ni_refcnt = 1; /* mark referenced */ lwkt_gettoken(&ilock, &ic->ic_nodetoken); TAILQ_INSERT_TAIL(&ic->ic_node, ni, ni_list); LIST_INSERT_HEAD(&ic->ic_hash[hash], ni, ni_hash); /* * Note we don't enable the inactive timer when acting * as a station. Nodes created in this mode represent * AP's identified while scanning. If we time them out * then several things happen: we can't return the data * to users to show the list of AP's we encountered, and * more importantly, we'll incorrectly deauthenticate * ourself because the inactivity timer will kick us off. */ if (ic->ic_opmode != IEEE80211_M_STA) ic->ic_inact_timer = IEEE80211_INACT_WAIT; lwkt_reltoken(&ilock); } struct ieee80211_node * ieee80211_alloc_node(struct ieee80211com *ic, uint8_t *macaddr) { struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); if (ni != NULL) ieee80211_setup_node(ic, ni, macaddr); else ic->ic_stats.is_rx_nodealloc++; return ni; } struct ieee80211_node * ieee80211_dup_bss(struct ieee80211com *ic, uint8_t *macaddr) { struct ieee80211_node *ni = (*ic->ic_node_alloc)(ic); if (ni != NULL) { ieee80211_setup_node(ic, ni, macaddr); /* * Inherit from ic_bss. */ IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid); ni->ni_chan = ic->ic_bss->ni_chan; } else ic->ic_stats.is_rx_nodealloc++; return ni; } static struct ieee80211_node * _ieee80211_find_node(struct ieee80211com *ic, uint8_t *macaddr) { struct ieee80211_node *ni; int hash; hash = IEEE80211_NODE_HASH(macaddr); LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr)) { atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */ return ni; } } return NULL; } struct ieee80211_node * ieee80211_find_node(struct ieee80211com *ic, uint8_t *macaddr) { struct ieee80211_node *ni; struct lwkt_tokref ilock; lwkt_gettoken(&ilock, &ic->ic_nodetoken); ni = _ieee80211_find_node(ic, macaddr); lwkt_reltoken(&ilock); return ni; } /* * Return a reference to the appropriate node for sending * a data frame. This handles node discovery in adhoc networks. */ struct ieee80211_node * ieee80211_find_txnode(struct ieee80211com *ic, uint8_t *macaddr) { struct ieee80211_node *ni; struct lwkt_tokref ilock; /* * The destination address should be in the node table * unless we are operating in station mode or this is a * multicast/broadcast frame. */ if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr)) return ic->ic_bss; /* XXX can't hold lock across dup_bss 'cuz of recursive locking */ lwkt_gettoken(&ilock, &ic->ic_nodetoken); ni = _ieee80211_find_node(ic, macaddr); lwkt_reltoken(&ilock); ni = _ieee80211_find_node(ic, macaddr); if (ni == NULL && (ic->ic_opmode == IEEE80211_M_IBSS || ic->ic_opmode == IEEE80211_M_AHDEMO)) { /* * Fake up a node; this handles node discovery in * adhoc mode. Note that for the driver's benefit * we we treat this like an association so the driver * has an opportunity to setup it's private state. * * XXX need better way to handle this; issue probe * request so we can deduce rate set, etc. */ ni = ieee80211_dup_bss(ic, macaddr); if (ni != NULL) { /* XXX no rate negotiation; just dup */ ni->ni_rates = ic->ic_bss->ni_rates; if (ic->ic_newassoc) (*ic->ic_newassoc)(ic, ni, 1); } } return ni; } /* * Like find but search based on the channel too. */ struct ieee80211_node * ieee80211_lookup_node(struct ieee80211com *ic, uint8_t *macaddr, struct ieee80211_channel *chan) { struct ieee80211_node *ni; int hash; lwkt_tokref ilock; hash = IEEE80211_NODE_HASH(macaddr); lwkt_gettoken(&ilock, &ic->ic_nodetoken); LIST_FOREACH(ni, &ic->ic_hash[hash], ni_hash) { if (IEEE80211_ADDR_EQ(ni->ni_macaddr, macaddr) && ni->ni_chan == chan) { atomic_add_int(&ni->ni_refcnt, 1);/* mark referenced */ break; } } lwkt_reltoken(&ilock); return ni; } static void _ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) { KASSERT(ni != ic->ic_bss, ("freeing bss node")); TAILQ_REMOVE(&ic->ic_node, ni, ni_list); LIST_REMOVE(ni, ni_hash); if (TAILQ_EMPTY(&ic->ic_node)) ic->ic_inact_timer = 0; (*ic->ic_node_free)(ic, ni); } void ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) { lwkt_tokref ilock; KASSERT(ni != ic->ic_bss, ("freeing ic_bss")); /* XXX DF atomic op */ crit_enter(); --ni->ni_refcnt; if (ni->ni_refcnt == 0) { crit_exit(); lwkt_gettoken(&ilock, &ic->ic_nodetoken); _ieee80211_free_node(ic, ni); lwkt_reltoken(&ilock); } else { crit_exit(); } } void ieee80211_free_allnodes(struct ieee80211com *ic) { struct ieee80211_node *ni; lwkt_tokref ilock; lwkt_gettoken(&ilock, &ic->ic_nodetoken); while ((ni = TAILQ_FIRST(&ic->ic_node)) != NULL) _ieee80211_free_node(ic, ni); lwkt_reltoken(&ilock); } /* * Timeout inactive nodes. Note that we cannot hold the node * lock while sending a frame as this would lead to a LOR. * Instead we use a generation number to mark nodes that we've * scanned and drop the lock and restart a scan if we have to * time out a node. Since we are single-threaded by virtue of * controlling the inactivity timer we can be sure this will * process each node only once. */ void ieee80211_timeout_nodes(struct ieee80211com *ic) { struct ieee80211_node *ni; lwkt_tokref ilock; u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/ restart: lwkt_gettoken(&ilock, &ic->ic_nodetoken); TAILQ_FOREACH(ni, &ic->ic_node, ni_list) { if (ni->ni_scangen == gen) /* previously handled */ continue; ni->ni_scangen = gen; if (++ni->ni_inact > IEEE80211_INACT_MAX) { IEEE80211_DPRINTF(("station %6D timed out " "due to inactivity (%u secs)\n", ni->ni_macaddr, ":", ni->ni_inact)); /* * Send a deauthenticate frame. * * Drop the node lock before sending the * deauthentication frame in case the driver takes * a lock, as this will result in a LOR between the * node lock and the driver lock. */ lwkt_reltoken(&ilock); IEEE80211_SEND_MGMT(ic, ni, IEEE80211_FC0_SUBTYPE_DEAUTH, IEEE80211_REASON_AUTH_EXPIRE); ieee80211_free_node(ic, ni); ic->ic_stats.is_node_timeout++; goto restart; } } if (!TAILQ_EMPTY(&ic->ic_node)) ic->ic_inact_timer = IEEE80211_INACT_WAIT; lwkt_reltoken(&ilock); } void ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) { struct ieee80211_node *ni; struct lwkt_tokref ilock; lwkt_gettoken(&ilock, &ic->ic_nodetoken); TAILQ_FOREACH(ni, &ic->ic_node, ni_list) (*f)(arg, ni); lwkt_reltoken(&ilock); }